<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
	<div id="app">
		<div>
			<input id="content" value=""/>
			<button onclick="up(event)">上移</button>
			<button onclick="down(event)">下移</button>
			<button onclick="del(event)">删除</button>
		</div>
	</div>
    添加到列表:<input id="newContent" /><button onclick="add(event)">添加</button>

    <script>
        var app = document.querySelector("#app");
        function up(e) {
			//e.target获取点击的元素
			//这一行上移
			
        }

        function down(e) {
			//这一行下移
        }

        function del(e) {
            //删除这一行
        }

        function add(e){
			//根据输入框添加一行
        }
    </script>
</body>

</html>